Rats and pigs most often contribute to the emergence of foci of infection, dogs and cats do not lag behind them. The infestation of these animals is often very high, sometimes significantly exceeding the infection of pigs and rats. Especially dangerous are their corpses in landfills, which can become a source of infection for rodents.
To get infected, it is enough for a person to eat a small piece (15-20 g) of meat. A lethal dose may be the ingestion of trichinous larvae in an amount of 5 specimens per kilogram of body weight. In the human stomach under the influence of digestive juice capsules of trichin dissolve and the larvae are released. They pass into the small intestine, where they quickly grow and after 3 days they turn into sexually mature forms.
Adult worms parasitize in the walls of the intestine, where the fertilization of females takes place, which produce 1500-2000 live larvae and die. Larvae along with blood and lymph are carried throughout the body (the migration period lasts 2-6 weeks) and settles in the fibers of striated muscles, mainly in the diaphragm, in the intercostal muscles, in the muscles of the larynx and in the eyes. The larva grows quite rapidly, around it a connective tissue capsule is formed, in which lime salts are deposited. The tissue of the host organism also participates in the formation of the envelope. In capsules, larvae remain viable for many years. Passing through the circulatory system, especially small vessels, they can damage them and cause hemorrhages in the tissue.
In mild cases, the disease can last several days, and in severe cases it can be delayed up to 5-8 weeks or more. After 10-45 days after infection, i.e. after eating affected meat, a person has a bad state of health, headache, body temperature sometimes reaches 39-40 °. Most often, it is the constant sign of the disease. Almost always at the beginning of the disease there is a swelling of the eyelids, then the face.
After 1-3 days during movement or with pressure, a person has pain in the muscles. In the blood, the content of eosinophilic leukocytes (eosinophilia) increases. Although the listed main symptoms do not always appear - in mild cases, trichinosis can be mistaken for influenza, and in severe cases it sometimes resembles typhoid fever. In severe disease, there may be complications: pneumonia, damage to the blood vessels and nerves, the brain, heart muscle, liver and kidneys. Particularly difficult and dangerous period of the disease is the time when the larvae migrate through the human body and their introduction into muscle fibers with the formation of calcareous capsules - serious complications can arise.
The diagnosis is made on the basis of the clinical manifestation of the disease, the study of blood and the use of some special diagnostic methods (immunological reactions). It is necessary to find out whether people who suffered from the disease a few days before the disease had pork or wild boar meat. If there are pieces of meat, they must necessarily be examined. In some doubtful cases resort to the study of the patient's muscles, extracting a small piece of muscle operatively.
With an average and severe course of the disease, the injured should be hospitalized. Mild cases of this disease can be treated at home under the constant supervision of an infectious disease doctor.
Disease in animals is difficult to recognize
Animals can also be infected through meat with this dangerous disease. True, how it proceeds in animals, while insufficiently studied, and the diagnosis in life is difficult to put. Veterinarians found that in the first two weeks of the disease, the general condition, decreased appetite, diarrhea, and a certain decrease in daily weight gain in young animals were noted in animals. In the blood, the increase in eosinophilic leukocytes is determined. Severe form of the disease leads to the death of the animal, especially dangerous period of development of intestinal trichinella or the time of encapsulation of larvae of Trichinella in muscles. An accurate diagnosis is made more often after the study of muscles, where the presence of trichinella is determined.
Do not leave carcasses of dead animals after removing skins on the territory of settlements or in the forest. This will become a source of infection of domestic animals and rodents. Use of meat of wild animals for pet food can only be done after careful examination. The corpses of the dead animals should be burned, and, if possible, sent to the scrap plants.
Among carnivorous trichinella are transmitted by eating certain animals by others. So, ermine and weasel can become prey to marten, ferret and other wild animals, and these animals are eaten by foxes. Badger, fox, raccoon dog, wild boar can be the prey of a wolf. Trichinosis from a wolf, a bear, a lynx that does not have practically enemies, can go after their death. The carrion is often eaten not only by predators and wild boars, but also by separate species of rodents and insectivorous mammals.
Insectivores and rodents are also a link in the spread of trichinella in nature. It is known that rodents are food for all predators, and for foxes and a number of other animals, rodent mice form almost the main food. Specialists infected Trichinella found in proteins, water rats, common voles, red forest voles, forest and field mice. Larvae of Trichinella in muscles are very resistant to minus temperatures, so corpses infected with trichinella can be a source of infection for a long time even in the cold season.
Importance in the fight against trichinosis has a microscopic examination of meat for the presence of pathogens. In Belarus, according to veterinary legislation, pig meat, as well as wild boar meat, must necessarily be subjected to microscopic testing at meat control stations, meat processing plants, slaughterhouses and slaughterhouses. To study from each carcass from the legs of the diaphragm, the intercostal or gastrocnemius muscles 24 muscle sections are taken, which are crushed between the glasses (in the compressor) and examined under a microscope. In the markets, samples for research can be taken from any pieces of meat. After the inspection, the stigma of veterinary and sanitary supervision is put.
If at least one Trichinella is found in the muscular sections, regardless of its viability, the meat is destroyed or goes into technical utilization. The perpetrators who sell non-cage meat are brought to criminal liability. Trichinella is killed when cooking pieces of meat no more than 8 cm thick for at least 2.5 hours. The usual thermal treatment of the larvae does not kill. Freezing or salting does not affect the vitality of Trichinella larvae. In the depths of salted ham, they last more than a year. It is not enough and smoking for their complete destruction.
It is necessary to follow the rules to avoid what you can infect through the meat of any member of your family:
- be sure to examine the trichinosis of animal meat;
- Do not buy meat and meat products outside the outlets, as well as pork meat products that do not have stamps or certificates of veterinary and sanitary examination;
- to destroy rodents in pig farms in the private sector;
- meat contaminated with Trichinella must be disposed of
A patient with trichinosis does not present a danger to others. However, he needs urgent treatment.